2 * i8k.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
4 * Copyright (C) 2001 Massimo Dal Zotto <dz@debian.org>
7 * Copyright (C) 2011 Jean Delvare <jdelvare@suse.de>
8 * Copyright (C) 2013 Guenter Roeck <linux@roeck-us.net>
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2, or (at your option) any
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23 #include <linux/module.h>
24 #include <linux/types.h>
25 #include <linux/init.h>
26 #include <linux/proc_fs.h>
27 #include <linux/seq_file.h>
28 #include <linux/dmi.h>
29 #include <linux/capability.h>
30 #include <linux/mutex.h>
31 #include <linux/hwmon.h>
32 #include <linux/hwmon-sysfs.h>
33 #include <linux/uaccess.h>
35 #include <linux/sched.h>
37 #include <linux/i8k.h>
39 #define I8K_SMM_FN_STATUS 0x0025
40 #define I8K_SMM_POWER_STATUS 0x0069
41 #define I8K_SMM_SET_FAN 0x01a3
42 #define I8K_SMM_GET_FAN 0x00a3
43 #define I8K_SMM_GET_SPEED 0x02a3
44 #define I8K_SMM_GET_TEMP 0x10a3
45 #define I8K_SMM_GET_DELL_SIG1 0xfea3
46 #define I8K_SMM_GET_DELL_SIG2 0xffa3
48 #define I8K_FAN_MULT 30
49 #define I8K_MAX_TEMP 127
51 #define I8K_FN_NONE 0x00
52 #define I8K_FN_UP 0x01
53 #define I8K_FN_DOWN 0x02
54 #define I8K_FN_MUTE 0x04
55 #define I8K_FN_MASK 0x07
56 #define I8K_FN_SHIFT 8
58 #define I8K_POWER_AC 0x05
59 #define I8K_POWER_BATTERY 0x01
61 #define I8K_TEMPERATURE_BUG 1
63 static DEFINE_MUTEX(i8k_mutex);
64 static char bios_version[4];
65 static struct device *i8k_hwmon_dev;
66 static u32 i8k_hwmon_flags;
67 static int i8k_fan_mult;
68 static int i8k_pwm_mult;
69 static int i8k_fan_max = I8K_FAN_HIGH;
71 #define I8K_HWMON_HAVE_TEMP1 (1 << 0)
72 #define I8K_HWMON_HAVE_TEMP2 (1 << 1)
73 #define I8K_HWMON_HAVE_TEMP3 (1 << 2)
74 #define I8K_HWMON_HAVE_TEMP4 (1 << 3)
75 #define I8K_HWMON_HAVE_FAN1 (1 << 4)
76 #define I8K_HWMON_HAVE_FAN2 (1 << 5)
78 MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
79 MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
80 MODULE_LICENSE("GPL");
83 module_param(force, bool, 0);
84 MODULE_PARM_DESC(force, "Force loading without checking for supported models");
86 static bool ignore_dmi;
87 module_param(ignore_dmi, bool, 0);
88 MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
90 static bool restricted;
91 module_param(restricted, bool, 0);
92 MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
94 static bool power_status;
95 module_param(power_status, bool, 0600);
96 MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
98 static int fan_mult = I8K_FAN_MULT;
99 module_param(fan_mult, int, 0);
100 MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
102 static int fan_max = I8K_FAN_HIGH;
103 module_param(fan_max, int, 0);
104 MODULE_PARM_DESC(fan_max, "Maximum configurable fan speed");
106 static int i8k_open_fs(struct inode *inode, struct file *file);
107 static long i8k_ioctl(struct file *, unsigned int, unsigned long);
109 static const struct file_operations i8k_fops = {
110 .owner = THIS_MODULE,
114 .release = single_release,
115 .unlocked_ioctl = i8k_ioctl,
120 unsigned int ebx __packed;
121 unsigned int ecx __packed;
122 unsigned int edx __packed;
123 unsigned int esi __packed;
124 unsigned int edi __packed;
127 static inline const char *i8k_get_dmi_data(int field)
129 const char *dmi_data = dmi_get_system_info(field);
131 return dmi_data && *dmi_data ? dmi_data : "?";
135 * Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
137 static int i8k_smm(struct smm_regs *regs)
141 cpumask_var_t old_mask;
143 /* SMM requires CPU 0 */
144 if (!alloc_cpumask_var(&old_mask, GFP_KERNEL))
146 cpumask_copy(old_mask, ¤t->cpus_allowed);
147 rc = set_cpus_allowed_ptr(current, cpumask_of(0));
150 if (smp_processor_id() != 0) {
155 #if defined(CONFIG_X86_64)
156 asm volatile("pushq %%rax\n\t"
157 "movl 0(%%rax),%%edx\n\t"
159 "movl 4(%%rax),%%ebx\n\t"
160 "movl 8(%%rax),%%ecx\n\t"
161 "movl 12(%%rax),%%edx\n\t"
162 "movl 16(%%rax),%%esi\n\t"
163 "movl 20(%%rax),%%edi\n\t"
167 "xchgq %%rax,(%%rsp)\n\t"
168 "movl %%ebx,4(%%rax)\n\t"
169 "movl %%ecx,8(%%rax)\n\t"
170 "movl %%edx,12(%%rax)\n\t"
171 "movl %%esi,16(%%rax)\n\t"
172 "movl %%edi,20(%%rax)\n\t"
174 "movl %%edx,0(%%rax)\n\t"
180 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
182 asm volatile("pushl %%eax\n\t"
183 "movl 0(%%eax),%%edx\n\t"
185 "movl 4(%%eax),%%ebx\n\t"
186 "movl 8(%%eax),%%ecx\n\t"
187 "movl 12(%%eax),%%edx\n\t"
188 "movl 16(%%eax),%%esi\n\t"
189 "movl 20(%%eax),%%edi\n\t"
193 "xchgl %%eax,(%%esp)\n\t"
194 "movl %%ebx,4(%%eax)\n\t"
195 "movl %%ecx,8(%%eax)\n\t"
196 "movl %%edx,12(%%eax)\n\t"
197 "movl %%esi,16(%%eax)\n\t"
198 "movl %%edi,20(%%eax)\n\t"
200 "movl %%edx,0(%%eax)\n\t"
206 : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
208 if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
212 set_cpus_allowed_ptr(current, old_mask);
213 free_cpumask_var(old_mask);
218 * Read the Fn key status.
220 static int i8k_get_fn_status(void)
222 struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
229 switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
242 * Read the power status.
244 static int i8k_get_power_status(void)
246 struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
253 return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
257 * Read the fan status.
259 static int i8k_get_fan_status(int fan)
261 struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
263 regs.ebx = fan & 0xff;
264 return i8k_smm(®s) ? : regs.eax & 0xff;
268 * Read the fan speed in RPM.
270 static int i8k_get_fan_speed(int fan)
272 struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
274 regs.ebx = fan & 0xff;
275 return i8k_smm(®s) ? : (regs.eax & 0xffff) * i8k_fan_mult;
279 * Set the fan speed (off, low, high). Returns the new fan status.
281 static int i8k_set_fan(int fan, int speed)
283 struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
285 speed = (speed < 0) ? 0 : ((speed > i8k_fan_max) ? i8k_fan_max : speed);
286 regs.ebx = (fan & 0xff) | (speed << 8);
288 return i8k_smm(®s) ? : i8k_get_fan_status(fan);
292 * Read the cpu temperature.
294 static int i8k_get_temp(int sensor)
296 struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
300 #ifdef I8K_TEMPERATURE_BUG
301 static int prev[4] = { I8K_MAX_TEMP+1, I8K_MAX_TEMP+1, I8K_MAX_TEMP+1, I8K_MAX_TEMP+1 };
303 regs.ebx = sensor & 0xff;
308 temp = regs.eax & 0xff;
310 #ifdef I8K_TEMPERATURE_BUG
312 * Sometimes the temperature sensor returns 0x99, which is out of range.
313 * In this case we return (once) the previous cached value. For example:
314 # 1003655137 00000058 00005a4b
315 # 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
316 # 1003655139 00000054 00005c52
318 if (temp > I8K_MAX_TEMP) {
320 prev[sensor] = I8K_MAX_TEMP+1;
324 if (temp > I8K_MAX_TEMP)
331 static int i8k_get_dell_signature(int req_fn)
333 struct smm_regs regs = { .eax = req_fn, };
340 return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
344 i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
348 unsigned char buff[16];
349 int __user *argp = (int __user *)arg;
355 case I8K_BIOS_VERSION:
356 val = (bios_version[0] << 16) |
357 (bios_version[1] << 8) | bios_version[2];
362 strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
367 val = i8k_get_fn_status();
370 case I8K_POWER_STATUS:
371 val = i8k_get_power_status();
375 val = i8k_get_temp(0);
379 if (copy_from_user(&val, argp, sizeof(int)))
382 val = i8k_get_fan_speed(val);
386 if (copy_from_user(&val, argp, sizeof(int)))
389 val = i8k_get_fan_status(val);
393 if (restricted && !capable(CAP_SYS_ADMIN))
396 if (copy_from_user(&val, argp, sizeof(int)))
399 if (copy_from_user(&speed, argp + 1, sizeof(int)))
402 val = i8k_set_fan(val, speed);
413 case I8K_BIOS_VERSION:
414 if (copy_to_user(argp, &val, 4))
419 if (copy_to_user(argp, buff, 16))
424 if (copy_to_user(argp, &val, sizeof(int)))
433 static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
437 mutex_lock(&i8k_mutex);
438 ret = i8k_ioctl_unlocked(fp, cmd, arg);
439 mutex_unlock(&i8k_mutex);
445 * Print the information for /proc/i8k.
447 static int i8k_proc_show(struct seq_file *seq, void *offset)
449 int fn_key, cpu_temp, ac_power;
450 int left_fan, right_fan, left_speed, right_speed;
452 cpu_temp = i8k_get_temp(0); /* 11100 µs */
453 left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
454 right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
455 left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
456 right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
457 fn_key = i8k_get_fn_status(); /* 750 µs */
459 ac_power = i8k_get_power_status(); /* 14700 µs */
466 * 1) Format version (this will change if format changes)
471 * 6) Right fan status
477 return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
480 i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
482 left_fan, right_fan, left_speed, right_speed,
486 static int i8k_open_fs(struct inode *inode, struct file *file)
488 return single_open(file, i8k_proc_show, NULL);
496 static ssize_t i8k_hwmon_show_temp(struct device *dev,
497 struct device_attribute *devattr,
500 int index = to_sensor_dev_attr(devattr)->index;
503 temp = i8k_get_temp(index);
508 return sprintf(buf, "%d\n", temp * 1000);
511 static ssize_t i8k_hwmon_show_fan(struct device *dev,
512 struct device_attribute *devattr,
515 int index = to_sensor_dev_attr(devattr)->index;
518 fan_speed = i8k_get_fan_speed(index);
521 return sprintf(buf, "%d\n", fan_speed);
524 static ssize_t i8k_hwmon_show_pwm(struct device *dev,
525 struct device_attribute *devattr,
528 int index = to_sensor_dev_attr(devattr)->index;
531 status = i8k_get_fan_status(index);
534 return sprintf(buf, "%d\n", clamp_val(status * i8k_pwm_mult, 0, 255));
537 static ssize_t i8k_hwmon_set_pwm(struct device *dev,
538 struct device_attribute *attr,
539 const char *buf, size_t count)
541 int index = to_sensor_dev_attr(attr)->index;
545 err = kstrtoul(buf, 10, &val);
548 val = clamp_val(DIV_ROUND_CLOSEST(val, i8k_pwm_mult), 0, i8k_fan_max);
550 mutex_lock(&i8k_mutex);
551 err = i8k_set_fan(index, val);
552 mutex_unlock(&i8k_mutex);
554 return err < 0 ? -EIO : count;
557 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 0);
558 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 1);
559 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 2);
560 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, i8k_hwmon_show_temp, NULL, 3);
561 static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
563 static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
564 i8k_hwmon_set_pwm, I8K_FAN_LEFT);
565 static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, i8k_hwmon_show_fan, NULL,
567 static SENSOR_DEVICE_ATTR(pwm2, S_IRUGO | S_IWUSR, i8k_hwmon_show_pwm,
568 i8k_hwmon_set_pwm, I8K_FAN_RIGHT);
570 static struct attribute *i8k_attrs[] = {
571 &sensor_dev_attr_temp1_input.dev_attr.attr, /* 0 */
572 &sensor_dev_attr_temp2_input.dev_attr.attr, /* 1 */
573 &sensor_dev_attr_temp3_input.dev_attr.attr, /* 2 */
574 &sensor_dev_attr_temp4_input.dev_attr.attr, /* 3 */
575 &sensor_dev_attr_fan1_input.dev_attr.attr, /* 4 */
576 &sensor_dev_attr_pwm1.dev_attr.attr, /* 5 */
577 &sensor_dev_attr_fan2_input.dev_attr.attr, /* 6 */
578 &sensor_dev_attr_pwm2.dev_attr.attr, /* 7 */
582 static umode_t i8k_is_visible(struct kobject *kobj, struct attribute *attr,
585 if (index == 0 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP1))
587 if (index == 1 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP2))
589 if (index == 2 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP3))
591 if (index == 3 && !(i8k_hwmon_flags & I8K_HWMON_HAVE_TEMP4))
593 if (index >= 4 && index <= 5 &&
594 !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN1))
596 if (index >= 6 && index <= 7 &&
597 !(i8k_hwmon_flags & I8K_HWMON_HAVE_FAN2))
603 static const struct attribute_group i8k_group = {
605 .is_visible = i8k_is_visible,
607 __ATTRIBUTE_GROUPS(i8k);
609 static int __init i8k_init_hwmon(void)
615 /* CPU temperature attributes, if temperature reading is OK */
616 err = i8k_get_temp(0);
617 if (err >= 0 || err == -ERANGE)
618 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP1;
619 /* check for additional temperature sensors */
620 err = i8k_get_temp(1);
621 if (err >= 0 || err == -ERANGE)
622 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP2;
623 err = i8k_get_temp(2);
624 if (err >= 0 || err == -ERANGE)
625 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP3;
626 err = i8k_get_temp(3);
627 if (err >= 0 || err == -ERANGE)
628 i8k_hwmon_flags |= I8K_HWMON_HAVE_TEMP4;
630 /* Left fan attributes, if left fan is present */
631 err = i8k_get_fan_status(I8K_FAN_LEFT);
633 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN1;
635 /* Right fan attributes, if right fan is present */
636 err = i8k_get_fan_status(I8K_FAN_RIGHT);
638 i8k_hwmon_flags |= I8K_HWMON_HAVE_FAN2;
640 i8k_hwmon_dev = hwmon_device_register_with_groups(NULL, "i8k", NULL,
642 if (IS_ERR(i8k_hwmon_dev)) {
643 err = PTR_ERR(i8k_hwmon_dev);
644 i8k_hwmon_dev = NULL;
645 pr_err("hwmon registration failed (%d)\n", err);
651 struct i8k_config_data {
664 static const struct i8k_config_data i8k_config_data[] = {
665 [DELL_LATITUDE_D520] = {
667 .fan_max = I8K_FAN_TURBO,
669 [DELL_LATITUDE_E6540] = {
671 .fan_max = I8K_FAN_HIGH,
673 [DELL_PRECISION_490] = {
675 .fan_max = I8K_FAN_TURBO,
679 .fan_max = I8K_FAN_HIGH,
683 .fan_max = I8K_FAN_HIGH,
687 static struct dmi_system_id i8k_dmi_table[] __initdata = {
689 .ident = "Dell Inspiron",
691 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
692 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
696 .ident = "Dell Latitude",
698 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
699 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
703 .ident = "Dell Inspiron 2",
705 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
706 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
710 .ident = "Dell Latitude D520",
712 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
713 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude D520"),
715 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_D520],
718 .ident = "Dell Latitude E6440",
720 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
721 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6440"),
723 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_E6540],
726 .ident = "Dell Latitude E6540",
728 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
729 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6540"),
731 .driver_data = (void *)&i8k_config_data[DELL_LATITUDE_E6540],
734 .ident = "Dell Latitude 2",
736 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
737 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
740 { /* UK Inspiron 6400 */
741 .ident = "Dell Inspiron 3",
743 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
744 DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
748 .ident = "Dell Inspiron 3",
750 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
751 DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
755 .ident = "Dell Precision 490",
757 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
758 DMI_MATCH(DMI_PRODUCT_NAME,
759 "Precision WorkStation 490"),
761 .driver_data = (void *)&i8k_config_data[DELL_PRECISION_490],
764 .ident = "Dell Precision",
766 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
767 DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
771 .ident = "Dell Vostro",
773 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
774 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
778 .ident = "Dell XPS421",
780 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
781 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
785 .ident = "Dell Studio",
787 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
788 DMI_MATCH(DMI_PRODUCT_NAME, "Studio"),
790 .driver_data = (void *)&i8k_config_data[DELL_STUDIO],
793 .ident = "Dell XPS M140",
795 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
796 DMI_MATCH(DMI_PRODUCT_NAME, "MXC051"),
798 .driver_data = (void *)&i8k_config_data[DELL_XPS_M140],
803 MODULE_DEVICE_TABLE(dmi, i8k_dmi_table);
806 * Probe for the presence of a supported laptop.
808 static int __init i8k_probe(void)
810 const struct dmi_system_id *id;
813 * Get DMI information
815 if (!dmi_check_system(i8k_dmi_table)) {
816 if (!ignore_dmi && !force)
819 pr_info("not running on a supported Dell system.\n");
820 pr_info("vendor=%s, model=%s, version=%s\n",
821 i8k_get_dmi_data(DMI_SYS_VENDOR),
822 i8k_get_dmi_data(DMI_PRODUCT_NAME),
823 i8k_get_dmi_data(DMI_BIOS_VERSION));
826 strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION),
827 sizeof(bios_version));
830 * Get SMM Dell signature
832 if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
833 i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
834 pr_err("unable to get SMM Dell signature\n");
839 i8k_fan_mult = fan_mult;
840 i8k_fan_max = fan_max ? : I8K_FAN_HIGH; /* Must not be 0 */
841 id = dmi_first_match(i8k_dmi_table);
842 if (id && id->driver_data) {
843 const struct i8k_config_data *conf = id->driver_data;
845 if (fan_mult == I8K_FAN_MULT && conf->fan_mult)
846 i8k_fan_mult = conf->fan_mult;
847 if (fan_max == I8K_FAN_HIGH && conf->fan_max)
848 i8k_fan_max = conf->fan_max;
850 i8k_pwm_mult = DIV_ROUND_UP(255, i8k_fan_max);
855 static int __init i8k_init(void)
857 struct proc_dir_entry *proc_i8k;
860 /* Are we running on an supported laptop? */
864 /* Register the proc entry */
865 proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
869 err = i8k_init_hwmon();
871 goto exit_remove_proc;
876 remove_proc_entry("i8k", NULL);
880 static void __exit i8k_exit(void)
882 hwmon_device_unregister(i8k_hwmon_dev);
883 remove_proc_entry("i8k", NULL);
886 module_init(i8k_init);
887 module_exit(i8k_exit);